A Perfect Storm: The Collision of Tropical Cyclones, Climate Change and Coastal Population Growth. Jeff Donnelly Woods Hole Oceanographic Institution

Transcription

1 A Perfect Storm: The Collision of Tropical Cyclones, Climate Change and Coastal Population Growth Jeff Donnelly Woods Hole Oceanographic Institution

2 Outline Background on hurricanes and climate Putting Hurricane Sandy in context Hurricane history in eastern MA What the long term (prehistoric) record tells us

3 What is a tropical cyclone? Conditions for genesis Warm tropical waters > 26 o C, 80 o F Minimal Wind Shear Aloft Prior disturbance Coriolis Deflection

4 Where do they occur?

5 Intensity

6 Tropical cyclones come in different sizes

7 Recent Hurricane Trends

8 What Might the Future Hold? N. Atl. Tropical SST N. Atl. Tropical Cyclones N. Hem. Mean Temp From Coumou and Rahmstorf, 2012 Nature Climate Change

9 What Might the Future Hold? N. Atl. Tropical SST N. Atl. Tropical Cyclones N. Hem. Mean Temp Frequency of hurricanes may increase (particularly intense storms) Using IPCC AR4 models Worst Case Best Case Modern

10 What Might the Future Hold? Frequency of hurricanes may increase (particularly intense storms) From Emanuel, 2013 PNAS Using IPCC AR5 models

11 What Might the Future Hold? Rate of sea level rise will continue to accelerate IPCC AR5

12 Hurricane Sandy billion in damage 148 fatalities

13 Hurricane Sandy SLOSH Simulation

14 Historical Northeast US Hurricanes

15 Historical Northeast US Hurricanes Black = cat 1 and 2 Red cat

16 Historical Northeast US Hurricanes Black = cat 1 and 2 Red cat

17 1821 Hurricane SLOSH Simulation William C. Redfield SLOSH input Track: ~known Translation speed: ~known (~65 km/hr (40 MPH)) Radius of maximum winds:? Intensity:? Though some inferences can be drawn from damage RMW = 46 km Intensity = 51 m/s (115 MPH)

18 1821 Hurricane vs. Sandy Hurricane Sandy 1821 Hurricane

19 1821 Hurricane vs. Sandy in NYC predicted tide surge+tide 1821 Sandy 0:00 4:00 8:00 12:00 16:00 20:00 24:00 Time September 3, Water level relative to mean sea level in 1821 (m) predicted tide surge+tide 0:00 4:00 8:00 12:00 16:00 20:00 24:00 Time October 29, Water level relative to mean sea level in 2012 (m)

20 1821 Hurricane vs. Sandy in NYC 1821 ~4 m of surge predicted tide surge+tide 0:00 4:00 8:00 12:00 16:00 20:00 24:00 Time September 3, Water level relative to mean sea level in 1821 (m) Sandy ~2.75 m of surge predicted tide surge+tide 0:00 4:00 8:00 12:00 16:00 20:00 24:00 Time October 29, Water level relative to mean sea level in 2012 (m)

21 2012 Storm tides in lower Manhattan Hurricanes Winter Storm Date 1 0 Maximum Water Level above MSL (m)

22 Storm tides in lower Manhattan If 1821 hit at high tide If Sandy hit at low tide Hurricanes Winter Storm Date Maximum Water Level above MSL (m)

23 Hurricane Sandy Storm Tide

24 Hurricane Sandy Storm Tide

25 Hurricane Sandy Storm Tide

26 Hurricane Sandy Storm Tide Long Beach

27 Long Beach Washover Pre Sandy Post Sandy

28 Long Beach Washover

29 What if Sandy hit SE New England?

30 What if Sandy hit SE New England? ~1.4 m of surge at Woods Hole

31 What if Sandy hit SE New England? Woods Hole, MA Monthly highest water Woods Hole tide gauge (above MHW) SLOSH simulation for Woods Hole (above MHW) SLOSH simulation for Woods Hole (above astronomical tide) meters (Carol) Hypothetical SE New England Sandy landfall feet (Donna) 1991 (Bob) Irene Sandy Year Boldt et al. (2010)

32 Why so much damage from Sandy?

33 Why so much damage from Sandy? Future home of Atlantic City (ca. 1833) today

34 Why so much damage from Sandy? Population growth in NJ coastal counties Atlantic Cape May Middlesex Monmouth Ocean Population Year Source: New Jersey Department of Labor and Workforce Development

35 US Hurricane Damage in 2005 USD 200 Damage (billions of 2005 USD) year From Pielke et al., 2008

36 US Hurricane Damage in 2005 USD But what if these storms were to strike today? 200 Damage (billions of 2005 USD) year From Pielke et al., 2008

37 US Hurricane Damage in 2005 USD Damage accounting for increased wealth and population 200 Damage (billions of 2005 USD) year From Pielke et al., 2008

38 US Hurricane Damage in 2005 USD Damage accounting for increased wealth and population Miami Damage (billions of 2005 USD) season 2005 season Sandy 1992 Andrew 1938 New England 1915 Galveston 1900 Galveston year From Pielke et al., 2008

39 Sea-Level Rise feet From Kemp and Horton, 2013 Journal of Quaternary Science

40 What about eastern MA? Hurricane Bob (1991) Storm Surge

41 What about eastern MA? Storm surge from the Great Colonial Hurricane of 1635

42 Storm surge from the Great Colonial Hurricane of 1635 John Winthrop (Governor of Massachusetts Bay Colony) The tide rose at Narragansett fourteen feet higher than ordinary, and drowned eight Indians flying from their wigwams William Bradford (Governor of Plymouth Colony) a mighty storm of wind and rain as none living in these parts, either English or Indians ever saw It caused the sea to swell to the south wind of this place above 20 foot right up and down, and made many of the Indians to climb into trees for their safety It blew down many hundred thousands of trees, turning up the stronger by the roots and breaking the higher pine trees off in the middle

43 Sedimentary Records of Hurricane Strikes Overwash sand layer Overwash sand layer WHOI 1 foot Overwash sand layer Overwash sand layer

44 Prehistoric Hurricanes and Climate Age (years CE) Hurricane-induced Sand Layers a - Event deposits Salt Pond, MA Coarse anomaly (%>63 m)

45 Prehistoric Hurricanes and Climate Events/century ʎ = 0.9 (0.002) (0.01) (0.06) (0.2) (0.6) (1) Age (years CE) a - Event deposits Salt Pond, MA Coarse anomaly (%>63 m)

46 Prehistoric Hurricanes and Climate Events/century ʎ = 0.9 (0.002) (0.01) (0.06) (0.2) (0.6) (1) Age (years CE) a - Event deposits Salt Pond, MA 0.01 Basin wide increases related to warm SST anomaly in deep tropics Coarse anomaly (%>63 m) Increased activity driven by warm SST anomaly off East Coast

47 Prehistoric Hurricanes and Climate Events/century ʎ = 0.9 (0.002) (0.01) (0.06) (0.2) (0.6) (1) Age (years CE) a - Event deposits Salt Pond, MA 0.01 b - Inlet Formation Outer Banks, NC 0.03 Landscape Impacts Coarse anomaly (%>63 m) Cuumulative Events

48 Landscape Impacts 17th Century erosion event Pattagansett Marsh, CT (van de Plassche et al. 2006) Erosive boundary potentially related Great Colonial Hurricane of 1635 Radiocarbon dated samples

49 Summary

50 Summary NJ/NYC were fortunate throughout the 20th century (unfortunately this was a time of unprecedented coastal development)

51 Summary NJ/NYC were fortunate throughout the 20th century (unfortunately this was a time of unprecedented coastal development) Storms of far greater intensity than Hurricane Sandy (and Bob) impacted the area historically (and prehistorically)

52 Summary NJ/NYC were fortunate throughout the 20th century (unfortunately this was a time of unprecedented coastal development) Storms of far greater intensity than Hurricane Sandy (and Bob) impacted the area historically (and prehistorically) Over the last two millennium historically unprecedented intense hurricane activity occurred during intervals of elevated sea surface temperatures

53 Summary The impacts of future hurricane activity will be greatly exacerbated by continuing sea-level rise and coastal population growth, regardless of whether or not we experience significant increases in hurricane landfalls

54 Summary The impacts of future hurricane activity will be greatly exacerbated by continuing sea-level rise and coastal population growth, regardless of whether or not we experience significant increases in hurricane landfalls Intervals of more frequent intense hurricane strikes significantly altered coastal landforms and ecosystems

55 Thank you! For more info see:

56 1821 Hurricane Storm Tide in NYC 15 Water level relative to mean sea level in 1821 (m) 4 Redfield (1831) - Water rose 13 feet (4 m) in lower Manhattan 3 10 predicted tide 2 surge+tide Water level relative to mean sea level in 1821 (ft) :00 4:00 8:00 12:00 16:00 20:00 24:00 Time September 3, 1821

57 Cat 3 curving west and making landfall in SE MA

58 Summary The impacts of future hurricane activity will be greatly exacerbated by continuing sea-level rise and coastal population growth, regardless of whether or not we experience significant increases in hurricane landfalls Intervals of more frequent intense hurricane strikes significantly altered coastal landforms and ecosystems We may see a loss of the protective services these landforms provide if we return to an active hurricane regime